Queen Creek Canyon is one of the dramatic vistas on the trail that loops through this amazing collection of desert plants. Along Queen Creek, the cottonwood trees have sprouted their brilliant green spring foliage. The Picket Post House crowns the top of the rocks at the left. This was the mansion built by Col. Boyce Thompson in 1928 and is now being managed by Arizona State Parks. Boyce Thompson Arboretum is a non-profit organization founded in 1924 by businessman and philanthropist, William Boyce Thompson.